Comparative proteomics of myocardial mitochondrial proteins in aging rats

AIM:To identify the proteins related to aging in the mitochondria of the heart. METHODS:Mitochondria were isolated from the hearts of adult (10-week) and old (12-month) rats (n=3). Total proteins extracted from the mitochondria were applied to the two-dimensional gel electrophoresis. The differentially expressed protein spots evaluated by a software were subjected to in-gel digestion, and analyzed by the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). ATP content in the heart was also measured. RESULTS:Eighty-four differentially expressed protein spots were observed, and fifteen of them were analyzed by MALDI-TOF- MS. Four proteins including creatine kinase, peroxiredoxin 2, Tu translation elongation factor and isocitrate dehydrogenase were up-regulated and 11 proteins including succinate dehydrogenase, malate dehydrogenase, aconitate hydratase, NADH dehydrogenase, ATP synthase H+ transporting, ATP synthase beta chain, heat shock protein 60, glucose-regulated protein 78, prohibitin, Aldehyde dehydrogenase 2 and voltage-dependent anion channel exhibited down-regulation in the aging group compared to the adult one. ATP content in the heart of old rats was significantly reduced as compared to that in adult rats (n=5, P<0.01). CONCLUSION:Significant changes in the mitochondrial protein expression in the aging heart were identified by the 2-DE electrophoretogram with high resolution and reproducibility. The functions of these identified proteins need to be further investigated.     

Analysis of serum biomarkers in human knee osteoarthritis

AIM: To analyze the proteomic components of the sera from knee osteoarthritis patients and normal people, and to search proteins that might serve as serum biomarkers for osteoarthritis diagnosis, treatment or pathogenesis. METHODS: Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) was applied to analyze the sera obtained from the patients with knee osteoarthritis (n=4) and normal controls (n=4). The differentially expressed proteins were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Western blotting analysis was applied to confirm the results. RESULTS: Comparative proteomic data of serum from the patients with osteoarthritis was successfully obtained. Eight differentially expressed protein spots were observed. Five up-regulated and 3 down-regulated proteins were identified. Western blot analysis confirmed that α₂-macroglobulin was increased. CONCLUSION: There are significant differences between serum proteins obtained from the patients with knee osteoarthritis and normal controls. α₂-Macroglobulin might be utilized as potential biomarkers for the diagnosis and treatment of osteoarthritis.     

辣椒CMS型雄性不育系与保持系花期叶片蛋白质组分析

采用双向凝胶电泳和计算机辅助分析方法,比较辣椒细胞质雄性不育系W9A与保持系W9B花期叶片蛋白质组,发现不育系与保持系花期叶片存在蛋白质(多肽)的差异,可能与细胞质雄性不育的形成有关。     

Effects of ginsenoside Rb1 on proteome from hippocampus of rats with epilepsy induced by Coriaria lactone

AIM: To explore the mechanism of development of Coriaria lactone (CL)-induced epilepsy and the neuroprotective effects of ginsenoside Rb1 (GRb1) on the process of epilepsy by identifying the proteins related to CL and GRb1 in rat hippocampus with two-dimensional electrophoresis (2-DE) technology.METHODS: The rat model of epilepsy was induced by CL. The rats in control group, CL epileptic group and GRb1 +CL epileptic group were decapitated and the hippocampus were collected. Two-dimensional electrophoresis was applied to separate the proteins from each group. Analysis of 2-DE maps was used to determine differential expression of proteins by ImageMaster 2D Platinum 5.0, and some differentially expressed protein spots were picked up for further identification by matrix-assisted laser sorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).RESULTS: Six proteins were successfully identified. Among these, the expression of brain creatine kinase, endophilin-A1 and UPF0628 protein C10orf96 homolog was lower in GRb1+CL epileptic group than those in CL epileptic group. The expression of cytochrome P-450, phosducin-like protein and bridging integrator 3 protein was lower in GRb1+CL epileptic group than those in control group.CONCLUSION: The protein expression profiles are significantly different among control group, CL epileptic group and GRb1+CL epileptic group. The identified proteins may be related to the neuroprotective effects of GRb1. Among these, brain creatine kinase, endophilin-A1 and UPF0628 protein C10orf96 homolog may be related to CL-induced seizures.     

Proteomic study on mice hepatic cell membrane proteins after exposed to hypoxia

AIM: To identify the differential expression of mice hepatic cell membrane proteins after hypoxic exposure.METHODS: The hepatic cells of C57BL/6 mice were cultured for 8 h under hypoxic or normoxic conditions and the membrane proteins were extracted. The differentially expressed membrane proteins were separated by two-dimensional electrophoresis. The technique of matrix-assisted laser desorption/ionization mass time-of-flight spectrometry(MALDI-TOF-MS) was used to analyze the proteins.RESULTS: Compared with the proteins extracted from the cells under normoxic condition with a threshold of 1.5-fold, 28 differentially expressed proteins were identified in the proteins extracted from the cells under hypoxic condition according to the database NCBInr 20071130, in which 9 were down-regulated and 7 were up-regulated, including prohibitin, cytochrome b-c1 complex subunit 1 and p22HBP.CONCLUSION: The results suggest that prohibitin, cytochrome b-c1 complex subunit 1 and p22HBP might play important roles in sensing of cellular oxygen and the related signal transduction pathways.     

Proteomic analysis of human endometrium during the implantation window

AIM: To establish a method for determining the differential expression of proteins in human endometrium during the implantation window and to analyze the correlation between altered expression of the proteins and endometrial receptivity. METHODS: A comparative proteomic strategy in a combination of two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was adopted to search the proteomic alternations in the endometria of pre-receptive pre-receptive [day 2 after luteinizing hormone surge (LH+2 d)] state versus the endometria of receptive (LH+7 d) state. Validation of annexin IV was performed by Western blotting. RESULTS: Approximate 2 555±98 polypeptide spots were revealed by densitometry analysis of the 2D protein maps in LH+2 d and LH+7 d endometrial tissues resolved in the linear range of pH 3~10 on the 2D gel, in which 31 proteins were found to be significantly changed, including 17 proteins up-regulated and 14 proteins down-regulated in LH+7 d samples. These 31 identified proteins were classified into 6 functional categories of the correlation with implantation process: cell migration or assimilation, enzymic activity, signal transduction and gene regulation, immunoregulation, vascularization, and blood clotting or fibrinolysis system. The same expression trend of annexin IV was confirmed by Western blotting. CONCLUSION: Human endometrium has a differential proteomic repertoire during the window of implantation. The 6 functional categories of differentially expressed proteins in the receptive endometrium indicate that they play an important role in transforming of the endometrium during the receptive state.     

Identification of serum differential proteins in colorectal adenoma and early malignantly transformed adenoma by proteomics

AIM: To investigate the associated proteins and sensitive biomarkers for early diagnosis of colorectal adenocarcinoma by comparing the results of differential proteomic analysis between colorectal adenoma and early malignantly transformed adenoma. METHODS: Two-dimensional gel electrophoresis was used to define patterns of protein expressions of colorectal adenoma and early malignantly transformed adenoma. Proteins expressed differentially among groups were detected, cut out and analyzed by MALDI-TOF/TOF mass spectrometry. RESULTS: Two-dimensional protein maps of colorectal adenoma and early malignantly transformed adenoma were analyzed with gel-analysis software, an average of 1 672 spots in adenoma, 1 732 in early malignantly transformed adenoma were observed. 28 spots of a 1.5-fold change were found, including 15 proteins down-regulated and 13 up-regulated in early malignantly transformed adenoma, in which 23 proteins were identified by mass spectrometry, the rate of identification was 82.14%. 13 differential proteins were attained, 8 were up-regulated and 5 were down-regulated, which was classified to 6 categories, including protease inhibitor, complement, immunoglobulin, keratoproteins, signal transduction protein and function-unknown proteins. CONCLUSION: The changes of serum proteins in early malignantly transformed adenoma from adenoma can be identified by proteomic technology. Proteins detected in the study may provide new biomarkers correlated with biological behavior of colorectal adenocarcinoma.     

应用2D-DIGE技术分析柑橘衰退病毒诱导的甜橙差异表达蛋白

【目的】为了研究柑橘衰退病毒(Citrus tristeza virus,CTV)诱导甜橙差异表达蛋白的分离和鉴定,【方法】以接种了CTV的甜橙植株为实验组,健康植株为对照组,利用双向荧光差异凝胶电泳(2D-DIGE)技术分析CTV诱导的甜橙差异表达蛋白。【结果】以t检验P<0.05和相对表达量≥1.5的水平作为判别标准,获得了91个CTV诱导的差异表达蛋白点,在实验组中含量高于对照组的蛋白56个,含量低于对照组的蛋白35个。通过MALDI-TOF质谱分析成功鉴定从中选择的37个蛋白点,其中19个蛋白功能明确,16个为预测或假定具有某种蛋白功能,包括与抗氧化相关的硫氧还蛋白、铁氧还蛋白、超氧化物歧化酶和抗坏血酸过氧化酶,与代谢相关的磷酸甘油酸酯水解酶、木葡聚糖内糖基转移酶、变味蛋白,分子伴侣热激蛋白,折叠酶肽酰脯氨酰顺反式异构酶,以及与光合代谢相关的蛋白等。【结论】CTV的侵染影响到甜橙各种复杂的生物学过程。     

Serum comparative proteomic analysis of radiation-induced hepatic injury in cirrhotic rats

AIM: To investigate the differential expression of serum proteins in cirrhotic SD rats for exploring the pathogenesis and identifying the potential biomarkers of radiation-induced hepatic injury. METHODS: Liver cirrhosis was induced in 8 healthy SD rats with subcutaneous injection of carbon tetrachloride (CCl₄) for 6 weeks and then the animals were randomly divided into 2 groups (4 rats in each group): control group (CCl₄ alone) and experimental group (CCl₄ plus radiation). The latter received hemi-liver radiation with single dose of 15 Gy while the former did not receive radiation. Total serum proteins of the 2 groups were extracted 6 h after radiation. Two-dimensional gel electrophoresis (2-DE) were performed to look for differentially expressed proteins. These proteins were then analyzed and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Western bloltting was used to validate the expression of heparanase and hepatocyte growth factor receptor in all independent series of serum samples. RESULTS: Two-dimensional gel images were acquired with good resolution and repetition. Thirty-three differentially expressed proteins were selected and 12 proteins were successfully identified by MS, in which 5 were up-regulated while 7 were down-regulated. The increased level of heparanase and decreased level of hepatocyte growth factor receptor were further confirmed by Western blotting. CONCLUSION: Twelve proteins associated with radiation-induced hepatic injury are successfully characterized by serum comparative proteomics. Heparanase and hepatocyte growth factor receptor might be useful for detecting and monitoring radiation-induced hepatic injury.     

Analysis of expressive proteome in human hepatocarcinoma cell HepG2 transfected with miR-26a mimics

AIM: To determine whether microRNA-26a(miR-26a) is involved in development of liver cancer by analysis of proteomic expression profile of human hepatocarcinoma cell HepG2 transfected with miR-26a mimics.METHODS: HepG2 cells were cultured by a routine method and transfected with miR-26a mimics for 48 h for cell cycle analysis. The expressive proteome profiles of HepG2 cells with or without miR-26a mimics treatment were established by the methods of two-dimensional electrophoresis separation following lysis of the cells and extraction of the proteins. The proteomic expression profiles were analyzed by comparative proteomics technique to discover the important protein spots with differential expression. The identification of the proteins was conducted by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS). RESULTS: miR-26a brought down the proliferation of HepG2 cells. Total 11 protein spots with alteration of expressive amounts more than 2 times were successfully identified in the proteomic expression profile of HepG2 cells treated with miR-26a mimics, including annexin A1, peroxiredoxin 4, proliferating cell nuclear antigen, apolipoprotein A1, cytochrome C oxidase subunit 5A, cyclin E2, ribose-phosphate pyrophosphokinase 3, cyclin-dependent kinase 1 and phosphatidylethanolamine-binding protein 1. Among these, the expression of 3 protein spots was up-regulated and 8 of them was down-regulated.CONCLUSION: miR-26a contributes to the anti-cancer effect by expressive regulation of the proteins mentioned above, or directly or indirectly controls the proliferation, differentiation and death of hepatocarcinoma cells.     

百合抗病无性系抗枯萎病的蛋白质组学分析

以百合抗病无性系和感病无性系为试验材料,开展了百合抗尖孢镰刀菌枯萎病的蛋白质组学研究,以期明确抗病无性系参与抗病反应的关键蛋白。利用蛋白质双向凝胶电泳技术,对被百合尖孢镰刀菌诱导0、24、48和72 h的抗病无性系和感病无性系进行差异蛋白分析。经质谱检测及数据库检索,鉴定了25个差异蛋白质点,其中10个鉴定为未知功能的蛋白,其余15个依据其相关功能分为4类,即防御反应相关蛋白、光合作用相关蛋白、糖类及能量代谢相关蛋白和热激蛋白。其中参与防御反应的病程相关蛋白（推定的抗病蛋白RPS2、推定的抗晚疫病同族蛋白R1C-3、过氧化物酶Q、抗坏血酸过氧化物酶和NBS-LRR类似蛋白）可能是百合抗病无性系介入抗病防御反应的关键蛋白。     

自交不亲和甘蓝亲和花粉授粉早期差异蛋白质分析

 为从蛋白质的角度揭示自交不亲和甘蓝亲和授粉早期花粉与柱头相互作用,将蛋白质组学方法应用于自交不亲和性甘蓝柱头与亲和花粉互作早期差异蛋白质的研究。结果表明,亲和授粉后3 ~ 5 min与1 h对比,有116个差异蛋白质点,而授粉后1 h与2 h差异不显著。按照特异表达与变化量大的蛋白质点优先原则,初步选取差异点中71个点做质谱分析,鉴定出31个可信差异蛋白质。与亲和授粉后3 ~ 5 min组相比,1 h组中特异表达蛋白质有19个,上调表达9个,下调表达3个。31种蛋白质的生物信息学分析表明,有两种蛋白与前人发现的与花粉管在柱头中生长发育相关蛋白相同,其他29种参与包括胁迫与防御应答在内多种生理过程。对早期差异蛋白中这种“既有促进花粉管发育的蛋白,也有与防御相关蛋白”现象分析表明,花粉管生长性侵入柱头的过程有可能伴随着柱头抗性的提高。     

Proteomics analysis of sera from Crohns disease patients and healthy individuals

AIM: To explore differentially expressed proteins of sera from Crohn's disease patients with comparative proteomics technology.METHODS: Two-dimensional differential in-gel electrophoresis was used to define patterns of protein expression in serum cross-labeled with variant CyDye from 4 patients and matched health adults.Proteins that showed differential expressions were analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry.RESULTS: Two-dimensional cross-labeled with variant CyDye protein maps of Crohn's disease patients and the health adults were gained successfully.Gel-analysis software identified differently expressed 29 spots Crohn's disease compared with that of health adults,22 of which were identified by using mass spectrometry,including serine/threonine-protein kinase ATR,leukocyte common antigen precursor CD45,60 kD SS-A/Ro ribonucleo-protein,etc.CONCLUSION: Proteomic analysis can identify the serum proteins with variance of Crohn's disease versus health,the different expressed proteins may providing probable new biomarkers correlated with biological behavior of Crohn's disease.     

Differential analysis of serum proteomics in Crohn's disease treated with infliximab

AIM: To identify the serum proteins that might serve as biomarkers for predicting mucosal healing (MH) in the patients with Crohn's disease (CD) treated with infliximab (IFX). METHODS: We collected serum samples before treatment (0 week, group A) and 14 weeks after treatment (group B) from 7 CD patients with IFX treatment who had achieved MH, as well as the serum samples from 7 CD patients who had not achieved MH (0 week, group C; 14 weeks, group D). Two-dimensional fluorescence difference gel electrophoresis was applied to analyze and compare the results of serum profiles between groups A and B, C and D, A and C, B and D. Matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry and bioinformatics tools were utilized to preliminarily identify and figure out the differentially expressed proteins. RESULTS: (1) In total, there were 44 differentially expressed spots, 36, 3, 10 and 31 differentially expressed spots were detected while comparing A with B, C with D, A with C and B with D, respectively. (2) Among those spots, 17, 2, 2 and 15 proteins were identified, respectively. In total, there were 19 differentially expressed proteins, including apolipoprotein E, apolipoprotein A-I, complement factor H, and so on. (3) Protein functional association networks were carried out based on STRING database. CONCLUSION: The serum protein profiles obviously change after IFX treatment in MH CD patients, and the serum protein profiles of MH patients are different from that of non-MH patients after IFX treatment. The 19 proteins we identified may serve as potential biomarkers for predicting MH in CD patients with IFX treatment.     

葡萄着色期果皮蛋白质组分析

为了研究葡萄不同着色期果皮中蛋白质表达特征,以着色初期、中期和后期等3个着色时期的葡萄果皮为研究对象,运用2-DE、MALDI-TOF/TOF-MS质谱技术以及生物信息学方法对差异蛋白进行分析,结果表明:(1)双向凝胶电泳显示,果皮着色3个时期有1050个高度重复的蛋白点,差异显著的蛋白点有162个,其中108个蛋白得到鉴定,有87个蛋白映射到葡萄蛋白质组数据库中;3个时期均表达的差异蛋白有20个,且随着果皮颜色加深,差异蛋白数量呈上升趋势。(2)GO分析显示,ATP合成酶β亚基(ATPβ)极显著富集于磷酸核糖代谢过程,对着色初期果皮生理代谢的能量需求具有重要意义。(3)KEGG分析表明,碳代谢、生物固碳、磷酸戊糖、氨基酸生物合成等代谢通路在果皮着色的不同时期显著富集。(4)qRT-PCR分析显示,S–腺苷甲硫氨酸合成酶基因(VvMETK4)在果皮着色后期表达量最高。     

Downregulation of beta tropomyosin protein expression in colon adenocarcinoma

AIM: To investigate the cancer associated proteins and sensitive biomakers for early diagnosis in colon adenocarcinoma by using proteomic technique.METHODS: Two-dimensional gel electrophoresis was used to define patterns of protein expression in adenocarcinoma tissue from 8 patients with matched normal colonic mucosa. Proteins expressed differently of a 2-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry. RESULTS: Two-dimensional protein maps of adenocarcinoma and normal colonic mucosa were gained successfully. Gel-analysis software identified an average of 3 289 spots in adenocarcinoma while 3 066 in normal mucosa and statistical filtering yielded 31 spots of a 2-fold change, 18 of which were identified by using mass spectrometry, including cytokeratin 8, cytokeratin 10, S100A6, beta tropomyosin (TMβ), protein disulfide isomerase, etc. Functional analysis revealed that these proteins were associated with adenocarcinoma cellular oncogenesia, proliferation, differentiation, metastasis and so on. The results of Western blotting validated that the expression level of TM β in colon adenocarcinoma was much lower than that in matched normal colonic mucosa.CONCLUSION: Proteomic analysis can identify the proteins with variance of colon adenocarcinoma versus normal colonic mucosa. Downregulation of TM β might serve as a new biomarker of colon adenocarcinoma.     

The relationship between the activity of phospholipase A2 and chronic hypoxic pulmonary hypertension

AIM:To study the relationship between the activity of phospholipase A₂ (PLA₂) and chronic hypoxic pulmonary hypertension. METHODS:29 healthy SD rats were randomly divided into normal control group, chronic hypoxic group and hypoxia plus Polidatin (PD) group. The model of rat chronic hypoxic pulmonary hypertension was made by method of intermittent isobaric hypoxia for 21 days. The mean pulmonary arterial pressure (mPAP) was measured by inserting a microcatheter into the pulmonary artery. RESULTS:After exposing hypoxia for 21 days, the mPAP, R/L+S, the PLA₂ activity, TXB₂, MDA in plasma and lung homogenate increased significantly, while 6-k-PGF_1α, SOD decreased significantly. Pretreatment with PD could relieve the changes mentioned above.CONCLUSION:PLA₂ plays an important inducing role through its metabolic products and the interactional radicals in the formation of chronic hypoxic pulmonary hypertension.     

Proteomic analysis of colon cancer

AIM: To investigate the cancer associated proteins and sensitive biomarkers in colon cancer. METHODS: Two-dimensional gel electrophoresis was used to define patterns of protein expression in cancer and matched morphologically normal colonic mucosa from 8 patients. Proteins that showed differential expression of a 2-fold change were cut and analyzed by MALDI-TOF mass spectrometry. RESULTS: Two-dimensional protein maps of cancer and matched normal tissue were gained successfully. Gel-analysis software identified an average of 3289 spots in cancer while 3066 in matched normal tissue and statistical filtering yielded 31 spots of a 2-fold change, 18 of which were identified by using mass spectrometry, including keratin 8, S100A6, protein disulfide isomerase, etc. Functional analysis revealed that these proteins were associated with cancer cellular oncogenesis, proliferation, differentiation and metastasis. CONCLUSION: Proteomic analysis can identify the proteins with variance of colon cancer versus normal colonic tissue as well as providing probable new biomarkers correlated with biological behavior of colon cancer.     

Comparative proteomics analysis of human osteosarcomas and benign tumors of bone

AIM: To analyze the proteomic components of the tissue from human osteosarcoma and benign tumor of bone, and to search the diagnostic markers of osteosarcoma. METHODS: Five samples of osteosarcoma and 5 additive samples from benign bone tumor were analyzed by a series of methods including immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2DE), deep purple staining. The ImageMaster 2DE analysis-software, as well as peptide mass fingerprint based on matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching were used for data processing. RESULTS: The average spots in osteosarcoma and the benign tumor of bone were 1 386±101 and 1 270±202, respectively. 22 peptide mass fingerprint (PMF) maps were obtained by MOLDI-TOF-MS and identified by searching the SWISS-PROT database. Compared with those in benign tumor of bone, 15 proteins were significantly up-regulated, especially zinc finger protein 133 (Znf133), lamin B and tailless complex polypeptide 1 (TCP-1). 7 down-regulated proteins were observed, with the absence of protein kinase C inhibitor protein 1 (KCIP-1) in osteosarcoma. CONCLUSION: The results suggest that an obviously differential proteomic expression exists between the osteosarcoma and benign tumor of bone. The overexpression of Znf133, lamin B, TCP1 and low-expression of KCIP-1 may play an important role in the development of osteosarcoma, and may serve as diagnostic markers/therapeutic targets of osteosarcoma.     

Characteristics of energy metabolism in brain mitochondria of rats exposed to hypoxia

AIM:To explore the characteristics of energy metabolism in brain mitochondria of rats exposed to acute and chronic hypoxia. METHODS: Animal grouping: Wistar rats were randomized into acute hypoxic group (AH), chronic hypoxic group (CH) and the control. Respiratory function, F₀F₁-ATPase activity, mitochondrial ATP, ADP and AMP contents and ATP production rate were measured respectively. RESULTS: In AH, brain mitochondrial respiratory state IV (ST₄) was increased, while respiratory control rate (RCR), mitochondrial ATP content, ATP production rate and F₀F₁-ATPase activity were decreased respectively. In CH, ST₄, RCR, mitochondrial ATP content and F₀F₁-ATPase activity were reversed partially.CONCLUSION: Acute hypoxia may impair brain mitochondria energy metabolism by way of depressing mitochondrial oxidative phosphorylation and ATP production and these parameters gain partial reablement during chronic hypoxia.